1.
Re-inventing middleware in a programming language
September 2019
Dr. Paul Fremantle, CTO and Co-Founder, WSO2
@pzfreo #ballerinalang

2.
(Almost)
Every programmer is
using and/or creating
APIs

3.
Existing languages treat the
network as simply I/O
Ballerina treats APIs, listeners,
endpoints, network types as first
class entities

4.
Ballerina is a modern, compiled, type safe,
concurrent programming language
Open Source implementations,
Apache Licensed
Open Specification,
Creative Commons Licensed

5.
Hello World

6.
caller hello
GET
Hello World

7.
Annotations

8.
caller hello
POST (name)
Hello, name!

9.
caller hello
POST (status)
response
twitter
tweet (status)
response

10.
○ Built in taint analysis
○ Built in API Gateway (JWT and OAuth)
○ Research on embedding SPIFFE into the language
○ First-class integration with Istio / Envoy
More info here:
https://github.com/prabath/ballerina-security

11.
Based on sequence diagrams

12.
○ A type defined by union of two or more other types
float | string v1 = "John";
float | string v2 = 457.68;
float | string
0.51
1.01
457.68
-11.0
“John”
“name”
“”
“bal”
// The return type of 'post' is a union of 'http:Response' and 'error'
http:Response | error response = orderEP -> post("/create", reqPayload)

13.
json is just a union - () | int | float | string | map<json> | json[]
// JSON object
json payload = { "orderdata": { "id": 1, "name": "XYZ", "price": 2500 } };
//Access object values
json orderid = payload.orderdata.id;
//JSON arrays
json orders = {
"orderdata": [
{ "id": 1, "name": "XYZ", "price": 2500 },
{ "id": 2, "name": "ABC", "price": 3000 }
]
};

14.
// Simple XML literal
xml x1 = xml`<name>Paul Fremantle</name>`;
// XML with namespaces
xmlns "http://wso2.com" as ns0;
xml x2 = xml `<name id="123" status="married">
<ns0:fname>Paul</ns0:fname>
<ns0:lname>Fremantle</ns0:lname>
</name>`;
// XML literal with interpolation
string lastName = "Fremantle";
xml x3 = xml`<lname>${lastName}</lname>`;
// Concat XML values
xml x4 = x1 + x2 + x3;

15.
Cloud native

16.
Concurrency

17.
future<int> f = start add( 2,2);
if (f.isDone()) {
int result = wait f;
io:println(result);
}
else if (f.isCancelled())
{
io:println("cancelled");
}
else
{
io:print("cancelling: ");
io:println(f.cancel());
}

18.
Batteries included

19.
○ Test
○ Documentation
○ Swagger tooling
○ gRPC tooling
○ Secret encryption
○ Docker / Kubernetes integration
○ Istio integration

20.
Serverless

21.
Observability

22.
Continuous Integration

23.
OpenAPI / Swagger

24.
$ ballerina openapi gen-contract hello -i demo.bal
Note: This is an Experimental tool shipped under
ballerina hence this will only support limited set
of functionality.
Successfully generated the ballerina contract at
location
/Users/paul/10demo/hello.openapi.yaml

25.
gRPC and ProtoBuf

26.
Ballerina syntax
Automatically creates this .proto

27.
My setup
● Ballerina 1.0.0
○ Tested this morning :-)
● Docker
○ 2.1.1.0 edge
○ Kubernetes: v1.14.3
● Visual Studio Code 1.38
● Ballerina vscode plugin

28.
https://ballerina.io/learn/by-example/

29.
https://github.com/ballerina-platform/ballerina-spec

30.
○ Join the Ballerina Hackathon
○ Write your first Ballerina program
○ Help us bridge Ballerina with your Apache project
○ Come to https://ballerina.io
○ Join the slack channel and/or ballerina-dev mailing list
○ Create a package
○ A connector to your Apache project!
○ Create issues
○ On the spec or implementation
○ If you have compiler skills, submit PRs on nBallerina or jBallerina

31.
Homepage https://ballerina.io/
Downloads https://ballerina.io/downloads/
Ballerina By Example https://ballerina.io/learn/by-example/
Github https://github.com/ballerina-platform/ballerina-lang